1. Field of the Invention
The present invention is related to an improved lamp structure for lamp strings, and especially to a lamp structure of which the longitudinal size is reduced, the lamp can be firmly set therein. Thereby, cost of production thereof can be lowered, and safety of use thereof can be increased.
2. Description of the Prior Art
As shown in FIG. 1 which shows an analytic perspective view of a conventional lamp structure, the lamp structure is comprised of a lamp bulb 1, a base 2, a socket 3 and two conductors 4. The lamp bulb 1 is provided on the lower end thereof with two metallic wires 11. The base 2 is provided therein with a receiving recess 21 to receive the lamp bulb 1 therein; the receiving recess 21 of the base 2 is divided into an upper portion and a lower portion. The upper portion is formed from a cylindrical wall of a main body 20, so that a cylindrical space is formed therein to receive the lamp bulb 1; the inner diameter of the receiving recess 21 is coincident with the external diameter of the lamp bulb 1. The lower portion of the receiving recess 21 is made as a rectangular hollow connecting portion 22 with a through hole on the bottom thereof (not shown) for extending therethrough the two metallic wires 11. In assembling, the two metallic wires 11 extend through the through hole to the outside of the base 2. The socket 3 is a hollow body with a receiving space 31 of which the upper portion has a larger space for insertion therein of the base 2 and of which the lower portion has a smaller space for insertion therein the two conductors 4 from below. Two metallic pieces 41 on the two conductors 4 are fixed in an engaging groove (not shown) in the socket 3. Thereby, when in insertion of the base 2, the metallic pieces 41 on the two conductors 4 can contact the two metallic wires 11 of the lamp bulb 1 to form a complete electric loop. However, such structure has the following defects:
1. In manufacturing lamp bulbs, it is unable to make every lamp bulb have same external diameter, difference of external diameters of them renders part of the smaller lamp bulbs to be subjected to being rotated by external force when the latter are placed in receiving the recesses 21 of bases 2. The metallic wires 11 beneath them thereby contact with each other to form short circuit, and a latent danger exists.
2. The bases 2 and the sockets 3 have larger lengths, they need more material for manufacturing; this results higher cost.
3. The metallic wires 11 of the lamp bulbs 1 have larger lengths which are at least 10 mm, this also results higher cost.
4. The lower portions of the bases 2 are subjected to water accumulating, and subjected to getting short circuit.
5. The bases 2 have larger depths, when in assembling, the metallic wires 11 of the lamp bulbs 1 are hard to align with the through holes on the bottoms of the bases 2 when they are to extend through the through holes, and such work is time consumptive.
In view of this, the main object of the present invention is to provide an improved lamp structure for lamp strings, the structure can have its longitudinal size reduced, and cost of production thereof can be lowered. That is, the longitudinal size of the base thereof is reduced; and correspondingly the longitudinal size of the socket is reduced, the length of the metallic wires 11 is shortened, thus cost of production can be largely reduced.
The secondary object of the present invention is to provide an improved lamp structure for lamp strings of which the lamp bulb is not subjected to being rotated. The bottom portion of the lamp bulb is completely set in the base to diminish space for rotation, and a plurality of ribs are provided in the socket to tightly abut against the external bottom portion of the lamp bulb, thereby, the lamp bulb is not subjected to being rotated by external force and safety of use thereof can be increased.
Another object of the present invention is to provide an improved lamp structure for lamp strings which is easy for assembling. Wherein, the longitudinal size of the socket is reduced, and the lower portion of the socket is partially opened, insertion of the metallic pins of the lamp bulb is more convenient and quicker.
Another object of the present invention is to provide an improved lamp structure for lamp strings which is not subjected to water accumulation. By virtue that the base thereof is shortened, and the bottom portion of the lamp bulb is completely set in the base, there is no space for water accumulation, and it is safer for use.
The present invention will be apparent in its particularity and technical contents after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings.